Container closure

ABSTRACT

A closure adapted to seal a container while being easily removable therefrom. Sealing means is provided for substantially hermetically sealing the container from its external environment. The sealing means is arranged to mate with the inside walls of the container and maintain wedging and sealing contact therewith. Closure releasing or lever means is connected to the sealing means for providing sufficient mechanical advantage to break the seal between the sealing means and the container upon the application of sufficient downward force to the lever means, whereby the closure is readily removable from the container.

United States Patent 1 Harper 1 51 Mar. 27, 1973 154] CONTAINER CLOSURE [76] Inventor: Paul W. Harper, 125 Lenore Ln., Centereach,N.Y.

[22] Filed: Jan. 8, 1971 [21] Appl. No.: 104,902

[52] U.S. CI. ..229/43, 220/43 P, 220/60 A [51] Int. Cl ..B65d 43/00, B65d 5/64 [58] Field of Search ..220/60 A, 60 R, 43, 42 B; 215/55; 229/15 B, 43; 09/281, 264, 265, 266, 267, 220

[56] References Cited UNITED STATES PATENTS 2,333,117 11/1943 Nyden ..220/43 P 2,049,228 '7/1936 Sebel ...220/60 A 2,510,824 6/1950 La Farge.... ....220/43 P 3,666,088 5 1972 Wingardh ..229 43 x FOREIGN PATENTS OR APPLICATIONS 306,466 2/1929 Great Britain ..220/60 A 910,907 2/1946 France ..220/43 P Primary ExaminerDavis T. Moorhead Attorney-Bryan, Parmelee, Johnson & Bollinger [57] Y ABSTRACT A closure adapted to seal a container while being easily removable therefrom. Sealing means is provided for substantially hermetically sealing the container from its external environment. The sealing means is arranged to mate with the inside walls of the container and maintain wedging and sealing contact therewith. Closure releasing or lever means is connected to the sealing means for providing sufficient mechanical advantage to break the seal between the sealing means and the container upon the application of sufficient downward force to the lever means, whereby the closure is readily removable from the container.

25 Claims, 7 Drawing Figures PATENTEDMARZYISYS 3,722,784

SHEET 10F 2 INVENTOR. P1121] 14 Harper 6770K EYS' PATENIEDMARNIQYs SHEET 2 BF 2 INVENTOIL Paul 01/ Harper BY CONTAINER CLOSURE BACKGROUND OF THE INVENTION This invention relates to a container closure or lid for sealing containers while being easily removable therefrom. More specifically, this invention relates generally to thermoplastic lids capable of sealing hot liquid containers, while being easily removable therefrom.

Generally, existing lids for disposable hot liquid containers have been found to be less than satisfactory. These lids generally fall into two classes; either they fit the container too loosely allowing the hot liquid, e.g. coffee, to easily spill therefrom or they fit the container too tightly and are difficult to remove. Often this latter class of lids is so difficult to remove that, in attempting to remove the lid, the contents are frequently spilled.

The general approach has been a compromise between the two classes of lids with the result that the lid is difficult to remove while at the same time fitting too loosely for proper sealing to prevent spillage. Such a compromise between sealing and ease of removal produces a lid which is unsatisfactory as viewed from either objective of providing effective sealing or ease of removal; that is when there is improved sealing the lid is difficult to remove and vice versa.

Additional factors have tended to aggrevate the problem of supplying an effective lid for hot liquid containers. An effective sealing lid should substantially hermetically seal the container. When the container is sealed the air entrapped therein is initially at room temperature, but once the air comes into contact with the hot liquid it is heated and expands, producing increased pressure which tends to open the lid. Further, if the sealed container is shaken the air will be heated more rapidly and the sudden surge of pressure may pop open the lid, possibly spilling hot liquid on'the hands of the user.

Another factor which must be considered is the surface tension or wetness of the liquid. It is easy to provide a seal when using cold water; however, once heated to near boiling temperature, the wetness of the water is increased and it will more easily penetrate through small openings. The addition of additives to water, e.g. coffee and artificial creams, further reduces the surface tension. Therefore, sealing of the hot liquid within a paper or thermoplastic container generally requires a very tight fitting lid, .too tight to provide easy opening.

Existing lids have attempted to provide sealing and prevent any popping open" due to pressure build up by utilizing a vent with or without a membrane in conjunction with a mechanical lock, i.e. an undercut in the container and/or in the lid. Generally, a diameter larger than the neck or restriction of the undercut of the other member is forced through this restriction to create a mechanical lock requiring a given pressure to again return the larger diameter through the neck or restriction of the undercut and thereby disengage the lid from the container. Such a sealing arrangement has been found to be less than satisfactory. Firstly, proper sealing of a fluid within a container is dependent upon the relationship between the pressures employed, and the durometer and elasticity of the material being used. A great enough pressure will even bring about a hermetic seal between rigid materials, e.g. steel, yet as pressures decrease, the rigidity of the sealing materials must decrease accordingly to permit one material to assume the configuration of the other and thereby effect sealing. Since the materials used for hot liquid containers are essentially standard, i.e. paper and thermoplastic lids and containers, there are inherent limitations as far as any change in the durometer of these materials are concerned. Insofar, as these materials and their elastic properties cannot be changed, the only alternative open is to accept these durometers as such and increase the pressures employed to obtain the proper relationship between the elasticity of materials and pressures applied to bring about a maximum sealing effect. In existing container and lid designs the pressures created when the largest diameter of one member passes through the smallest diameter or neck of the undercut of the other member are not sufficient to bring about sealing; once passage through the neck has been accomplished, less pressure will exist since the diameter of the undercut is larger than the diameter of the neck. Since the pressure at the neck is insufficient for sealing, scaling is also deficient at a location of even less pressure, namely at the undercut.

SUMMARY OF THE INVENTION The present invention solves the problems encountered by prior lids through utilization of a basically different approach. Under the-divine guidance of Jesus Christ, a closure was developed which will substantially hermetically seal a hot liquid container and maintain the seal under essentially any conditions encountered by the sealed container during transport, while having means for applying sufficient mechanical advantage to the closure to make it easily removable from the hot liquid container.

The concept of utilizing a vent and undercuts has been discarded. Means has been provided for maximizing the sealing pressures of the materials being used and maintaining this maximum pressure. Means has been provided for furnishing sufficient mechanical advantage to the closure for easy disengagement thereof even while employing maximum sealing pressures.

It is an object of the present invention to provide a closure which will tightly seal a container while being easily removable therefrom.

It is a further object to provide a container closure capable of providing an effective seal under substantially all conditions to be encountered by carry-out containers, i.e. maintaining a seal when the container is subjected to movement, tipping, extreme shaking,'or even if turned upside down or the entire sealed container should accidentally fall on the floor.

It is a further object to provide a container closure which can be easily removed from a container.

It is a further. object to provide a container closure which will substantially hermetically seal a hot liquid container.

It is a further object to provide a container closure with spring-like action causing a popping sound upon disengagement from the container to improve the operation of the closure and increase its appeal to a consumer.

It is still a further object of the present invention to provide a container closure which can be readily manufactured as a disposable lid, so that after its initial use it cannot be reused, or with slight modification become a fully reusable container closure.

It is a still further object of the present invention to i provide a container closure which is capable of being readily closed with the hand, with a closing implement, or with fully automatic machinery.

It is a still further object to provide a container closure that will provide an effective seal even if the container opening is not completely round, e.g. with paper cups having an overlap at the seam.

It is a still further object to provide a container closure that will effectively seal even if the container is not made to close tolerances.

It is a still further object of the present invention to provide a container closure which is attractive, easy to use, and relatively inexpensive to manufacture.

It is a still further object to provide a closure which may be readily opened with one hand, so that the other hand is free to hold other food, e.g. a sandwich.

Briefly, the present invention has generally removed the problems associated with prior art lids while providing a container closure fulfilling the above objects by utilizing a container closure which is adapted to seal a container while being easily removable therefrom. Sealing means is arranged to mate with the inside walls of the container and maintain wedging and sealing contact therewith. Closure releasing or lever means is connected to the sealing means for providing sufficient mechanical advantage to release the sealing means from the container upon application of sufficient downward force to the lever means, whereby the container closure is readily removable from the container.

Otherobjects, aspects and advantages of the present invention will be more fully understood when the detailed description is considered with the drawings, as follows:

DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of the container closure;

FIG. 2 is a bottom plan view of the container closure shown in FIG. 1;

FIG. 3 is a sectional view of the container closure shown in FIG. 1 taken along line 33;

FIG. 4 is an enlarged sectional view of the container closure shown in FIG. 3 sealingly positioned in a container;

FIG. 5 is a top plan view of an alternate configuration for the container closure;

FIG. 6 is a sectional view taken along line 77 of FIG. 5; and

FIG. 7 is an enlarged sectional view of the container closure shown in FIG. 6 sealingly positioned in a container and about to be removed.

DETAILED DESCRIPTION Referring to FIGS. 1 through 5 the container closure 10 is shown. The closure 10 includes a sealing means 12 and closure releasing or lever means 14. The lever 14 is shown as a radial skirt or truncated cone segment, formed from a thin sheet of thermoplastic, extending acutely outwardly and upwardly from the sealing means 12. A satisfactory angle of inclination from the horizontal for the radial skirt 14 has been found to be between and 35 degrees. The radial skirt 14 is connected to the sealing means 12 at its inner diameter 16 and extends acutely outwardly and upwardly therefrom to its outer diameter 18. By depressing the radial skirt 14 at its outer diameter or end 18 sufficient mechanical advantage is applied to the sealing means 12 so that the sealing means 12 is disengaged from sealing contact with the inside walls 20 of the container 22 as the radial skirt 14 generally reverses position, i.e. the 25 angle pointing acutely upward will now be a 25 angle pointing acutely downward.

The interconnection of the radial skirt 14 and sealing means 12 may be aptly described as a hinge. The connection may be abrupt and well defined for fracture and separation of the radial skirt 14 from the sealing means 12, during the second reversal of the radial skirt 14 to provide a non-reusable closure. Alternatively, the connection may have a slight radius for allowing fracture and separation during subsequent reversals of the radial skirt 14.

The rim 24 of the container 22 constitutes the fulcrum or support for this lever action. Particularly, with reference to FIG. 4, at the beginning of the lifting action the ratio between the two moment arms, i.e. between the outer diameter 18 and the fulcrum and the inner diameter 16 connected to the sealing means 12, is greater than the ratio at the close of the lifting action. This shifting fulcrum construction allows generation of the maximum force at the beginning of the lever action to break the seal and generation of the maximum amount of motion at the end of the lifting action when maximum force is no longer required, but distance of separation between the sealing means 12 and the inside walls 20 of the container 22 becomes essential fortotal separation and disengagement of the container closure 10 from the container 22. This layer will also advantageously provide a secondary seal between the radial skirt 14 and the rim 24 when the closure 10 is in sealing and wedging contact with the container walls 20 in the absence of reinforcing trusses.

In some cases, due to exceedingly great variations in the size of the containers 22, total disengagement may not be brought about by the downward pressure of the hand. In such cases, total disengagement may be achieved by squeezing or pressing the radial skirt 14 inwardly towards the axis 26 of the container 22 providing a cam action between the radial skirt 14 and the rim 24 to force the sealing means 12 away from the inside walls 20.

The radial skirt 14 should have sufficient thickness or rigidity to resist deflection and be of sufficient width to be readily actuated by human fingers. To provide such rigidity it has been found advantageous to utilize reinforcing trusses 28. These trusses 28 are radially oriented along the radial skirt 14, extending between the inside and outside diameters 16 and 18, respectively, and generally as narrow as the vacuum forming of pressure forming processes will permit.

Ideally, the radial skirt 14 should be essentially a thin sheet of thermoplastic material having a configuration which offers optimum reversing characteristics. Any circumferial deformation in the radial skirt 14 will greatly impair reversal. Radial deformations offer little resistance to the reversing process provided they are thin enough; the width of a radial deformation actually constitutes a circular deformation which as previously indicated resistsreversal.

A large lever or radial skirt may facilitate lifting. However, a large radial skirt requires additional material and storage space. A smaller radial skirt 14 is therefore generally preferred even though the smaller radial skirt 14 increases proportionally the amount of force required to be applied to the radial skirt 14 to open the sealed container.

To affect reversal of the angular position of the radial skirt 14, pressure is generally applied thereto manually. The depression of the radial skirt 14 will generally provide three effects:

1. Breaking and overcoming the sealing pressure between the inside walls 20 of the container 22 and the sealing means 12;

2. Inducing stresses into the radial skirt 14; and

3. Changing the configuration of the closure at the fulcrum of the lever or radial skirt 14, since the angle between the radial skirt 14 and the sealing means 12 is changed some 50 to 70 as the radial skirt 14 undergoes reversal.

To disengage the closure without the popping or snapping sound of the radial skirt 14 may be desirable for some applications and would require less force. To achieve this objective, the trusses 28 extend to the outside diameter 18 of the radial skirt 14 to provide a gradual lifting and reversal of the radial skirt 14. However, this may be undesirable from a merchandising point of view since a positive, sound-emitting, snap action is more definitive than gradual action with no clear beginning or end. The user upon hearing the snapping sound is made aware that the lever or radial skirt 14 has completed its function of opening the container 22.

The deformation of the thermoplastic closure 10 may be advantageously used to aid in the operation of the closure 10. When vacuum forming the closure 10, the closure 10 is initially formed in the open position, i.e. the radial skirt 14 extending downwardly. By stripping the closure 10 from the mold so that the radial skirt 14 is reversed into a closed position, i.e. the radial skirt extending acutely outwardly and upwardly in its normal operating position, latent stresses are induced in the thermoplastic closure 10. Therefore, relatively light pressure on the radial skirt 14 will be sufficient to cause reversal thereof from a closed or upward position to an open or downward position. The induced stresses thereby aid the user in easily removing the closure 10 from the container 22.

Referring particularly to FIGS. 3 and 4, the sealing means 12 includes a substantially truncated cone segment having the same taper or angle as the taper or angle of the container 22 relative to the container axis 26. Since hot liquid containers 22, e.g. coffee containers, are generally conical in shape a taper-lock is effected between the inside walls 20 of the container 22 and the truncated cone segment 36. The taper or angle between the container walls 20 and the container axis 26 is generally found to be approximately 5 degrees. Such a slight angle, if the coefficient of friction is not too low, affords a very satisfactory locking angle; the

angle is small enough to allow generation of sufficient sure being forced upwardly by the cam action of the container walls 20 when the lever is depressed. With this arrangement less vertical travel is required to break the seal and therefore the angle of the radial skirt 14 could be smaller.

Referring particularly to FIGS. 3, 4, 6 and 7, the truncated cone segment 36 has a reinforcing means or peripheral circular ridge 38 extending inwardly around the periphery thereof. The circular ridge 38 aids in the increasing of the sealing pressure between the truncated cone segment 36 and the inside walls 20 of the container 22 for the following reasons:

1. The circular ridge'38 increases the rigidity of the sealing means 12 giving strength to areas of the closure 10 which may be weakened by receiving too much heat from the hot liquid or air;

2. The sealing pressure increases in inverse proportion to the amount of surface of the closure 10 brought into contact with the inside walls 20. To increase the sealing pressure, line contact is achieved with the container walls 20 through sealing rings 40 and 42, respectively; and

3. Whatever fluid passes into the circular ridge 38, beyond the first cone segment portion portion or sealing ring 40, cools off and has less of a softening effect on the second cone segment portion or sealing ring 42, providing better sealing, (assuming the ridge 38 is of sufficient width and depth to provide entrapment and cooling of the fluid). Cold fluid has less wetness than hot fluid and therefore will not penetrate as easily.

For the above reasons the line contact against the inside walls 20 obtained by the two sealing rings 40 and 42, whichincrease in diameter according to the taper of the truncated cone segment 36, will therefore provide improved sealing characteristics.

The sealing means 12 also includes a substantially flat surface or cover 44 having the same configuration as the rim 24 of the container 22 for fitting therein.

It is advantageous to provide a force or stress distribution ring 45 arranged about the periphery of the cover 44 at the interconnection with the sealing means 12. This stress distribution ring 45 serves to resist any tendency of the cover 44 to pull the sealing rings 40 and 42 away from contact with the container walls 20. The force distribution ring accomplished this result by distributing the inserting forces acting on the sealing means 12 equally about the sealing rings 40 and 42.

The cover 44 may also have a locating means shown as a circular ridge 46, for receiving and locating the bottom of a second container (not shown) which may be employed to wedge the sealing means 12 into sealing contact with the inside walls 20 of the container 22. Additionally, the circular ridge 46 may facilitate the vertical stacking of sealed containers 22 one upon the other for ease in transporting the same.

Referring particularly to FIG. 5, it may be advantageous to utilize two opposed tabs 30 and 32 respectively, connected to a gradually tapering radial skirt 34. The tapered radial skirt 34 has a configuration, i.e. noncircular, which provides a gradual wave motion. The wave motion starts at the tabs 30 and 32 (x-axis) and finishes at the y-axis, opposite thereto.

Referring to FIGS. 5 through 7, the cover 44 may also advantageously include a reversible surface or bellows 48 normally extending downwardly therefrom.

The reversible surface or bellows 48 normally maintains a substantially convex configuration, see FIG. 6. However, due to the internal pressure of the hot liquid within the container 22, upon insertion into the container 22, the reversible surface or bellows 48 reverses into a concave configuration, thereby increasing the volume within the sealed container 22 and decreasing the resultant internal pressure to increase the sealing capability of the closure 10, see FIG. 7.

The entire closure 10 may be advantageously molded as an integral unit from a single sheet of impermeable thermoplastic material. Further, as previously described, the radial skirt 14 may be formed in an open position and upon removal from the mold urged into a closed position thereby aiding in reversal of theradial skirt when acted upon by the downward force. The closure 10 may also be advantageously formed of a low durometer material to provide increased sealing capability between the sealing means 12 and container walls 20. It may also be desirable for some applications to add a low durometer substance to the sealing means 12 to achieve a low durometer.

As previously discussed, it may also be advantageous to have the closure 10 made out of a material having a high coefficient of friction relative to that of the container 22, so that the closure 10 may readily resist any vertical displacement due to internal pressures caused by hot liquid within the container 22 when the closure 10 is in sealing contact with the inside walls of the container 22.

In operation, the cover 44 is gentley fitted within the rim 24 of the container 22. Pressure is exerted on the cover 44 with human fingers, with a second container or other implement (not shown) as previously described. The pressure exerted on the cover 44 forces the sealing means 12 into an interlocking wedging relationship with the inside walls 20 of the container 22 adjacent the rim 24. Sealing rings 40 and 42 are thereby placed in line sealing contact with the container walls 20; force distribution ring 45 distributes the inserting forces equally about the sealing rings 40 and 42. Thus, the closure 10 is hermetically sealed to the container 22.

Additionally, as the sealing means 12 is brought into sealing engagement with the container walls 20, if the closure includes a bellows 48, the bellows 48 will move toward a concave configuration increasing the internal volume of the sealed container 22 and thereby decreasing the internal pressure within the container 22.

Once the closure 10 is in a sealing position, the closure 10 may be readily removed from the container 22 by simply depressing the radial skirt 14 with the hand or cupped palm, see FIG. 4, or by depressing tabs and 32 located approximately 180 apart with the thumb and index finger, see FIG. 7.

Depression of the radial skirt 14 will provide a lever action about the rim 24 which breaks the seal and disengages the closure 10 from the container 22;.the radial skirt l4 undergoing a reversal. Further, the radial skirt 14 provides a popping sound at the completion of the reversal to notify the user that the closure 10 is completely disengaged from the container 22. (If tabs 30 and 32 are employed a wave-like reversal motion beginning at the x-axis and terminating at the y-axis may be effected, see FIG. 7.)

the appended claims.

What Is Claimed Is:

1. A closure adapted to seal a container while being easily removable therefrom, said closure comprising:

means for sealing the container, said sealing means having a tapering sealing portion arranged-to mate with the inside walls of the container and capable of generating radial pressure thereagainst for maintaining wedging, sealing, contact therewith; and

lever means extending radially outwardly from the container rim and being flexibly connected to said sealing means for providing sufficient mechanical advantage to release the closure from the container upon the application of sufficient downward force to said lever means whereby upon the application of sufficient force to said lever means said sealing means is readily disengaged from the walls of said container, said lever means being of suffi cient strength to resist deflection under the application of the downward force and of sufficient width to be easily activated by human fingers;

said lever means being arranged for contact with the rim of container and shaped so that upon application of the downward force the fulcrum will shift toward the point of application of the downward force along said lever means so that the ratio between the moment arms acting about the fulcrum is constantly changed during the application of the downward force, whereby maximum force is initially applied to break the seal generated by said sealing means and maximum motion is applied at the end of the application of the downward force to provide total separation between the closure and container.

2. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein:

said lever means includes reinforcing means to aid in resisting deflection upon the application of the downward force.

3. A closure adapted to seal a container about its rim while being easily removable therefrom, as claimed in claim 1 wherein:

said lever means extending radially outwardly from the container rim is in the form of a skirt adapted to provide a secondary seal against the rim of the container when the closure is inserted within the container.

4. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 3 wherein:

said lever means includes trusses extending radially along said radial skirt toward the inner and outer diameters thereof, whereby said radial skirt may be reversed into a downward and outward position relative to said sealing means under application of the downward force thereby emitting a snapping sound, said trusses being sufficiently narrow in width to permit reversal of said radial skirt between the portions of said lever means at which the downward force is applied.

5. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 3 wherein:

said lever means includes trusses extending radially to the outer diameter of said radial skirt to provide a gradual lifting and reversal of said radial skirt when acted upon by the downward force without producing a snapping sound.

6. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein:

said lever means and said sealing means are abruptly connected, said lever means and said sealing means forming an abrupt intersection to provide abrupt reversal in the position of said lever means under the influence of the downward force to provide fracture and separation of said lever means from said sealing means during a second reversal.

7. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein:

said lever means and said sealing means form a slight radius at their connection to provide fracture and separation of said lever means relative to said sealing means during a subsequent application of the downward force.

8. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein:

said lever means and said sealing means form a radius at their connection, said radius being sufficiently large to prevent separation andfracture upon application of the downward force, while being sufficiently small to permit reversal in the position of said lever means.

9. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein:

said lever means and sealing means intersect abruptly at certain portions'of their connection while the remaining portions of their connection have a slight radius to provide fracture at said abruptly intersecting portions while preventing complete separation of said lever means from said sealing means due to said slight radius connecting portions.

10. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein:

said lever means and sealing means are integrally connected, said closure having a memory of reversal at said integral connection.

llf A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein:

said sealingmeans is shaped in the form of a truncated cone segment, said truncated cone segment being arranged for insertion of said sealing means into the container and having a taper which is substantially the same as the taper of the-walls of the container, to provide wedging mating contact therewith, whereby said wedged truncated cone segment will generate radial pressure against the inside walls of the container forming a seal therewith.

12. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 11 wherein:

said truncated cone segment includes a plurality of sealing rings for line contact with the container walls to increase the sealing pressure therebetween, said sealing rings being of increasing diameter to match the taper of said truncated cone segment.

13. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 11 wherein:

said truncated cone segment includes reinforcing means for increasing the resistance of the sealing means to deflection while said sealing means is wedged against the inside walls of the container.

14. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 13 wherein:

said reinforcing means is an inwardly directed peripheral ridge of sufficient width and depth to further allow entrapment and cooling of portions of any heated gases and liquids present within the container, thereby creating a temperature differential along said truncated cone segment on the opposite sides of said ridge to increase the sealing capability of said sealing means and to increase the wedging pressure per unit area of said truncated cone segment acting against the inside walls of the container.

15. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein:

said sealing means has a low durometer to provide increased sealing action between said sealing means and the inside walls of the container.

16. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein:

said sealing means has a high coefficient of friction relative to the walls of the container to resist vertical displacement due to the action of any internal pressures resulting from any heated gases and liquids present within the container.

17. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein:

said lever means and sealing means are integrally formed of an impermeable material so that said closure is hermetically sealed to the container.

18. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 including:

reinforcing means associated with said sealing means for equally distributing the reaction radial forces exerted on said sealing means from the container walls around said sealing means to maintain said sealing means in sealing contact with the inside walls of the container.

19. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein:

said sealing means includes a cover connected thereto, said cover having the same configuration as the rim of the container for fitting therein, said cover further having stress distribution means for resisting deflection when the downward force is exerted thereupon to seal the container, said stress distribution means distributing the downward container, whereby the reversal of said reversible bellows increases the effective volume of the sealed container thereby decreasing the resultant internal pressure to increase the sealing capability of said closure. 23. A closure adapted to seal a hot liquid container comprising:

means for substantially hermetically sealing the container to effectively seal the inside of the container and any contents therein from its external environthereto, said cover having the same configuration as the rim of the container for fitting therein, said cover further having a means for receiving and merit, said sealing means having a configuration to mate with the inside walls of the container and arranged for wedging insertion into the container to locating the bottom of a Second container for generate radial pressure against the inside walls of wedging Said cover into the first container and to the container forming a hermetic seal therewith; stack individual sealed containers one upon the and 0th for ease in transporting a puramy of at least one peripheral ridge of sufficient width and dividual Sealed containers depth to allow entrapment and cooling of portions of an heated ases resent within the container, A closure adapted to Seal a coniamer f F thereby creatin g a te mperature differential along easily removable therefrom, as claimed in claim 1 said sealing means on the portions of said sealing wherem: means on opposite sides of said ridge to increase 531d Sealmg means Includes a cover Connected the sealing capability of said sealing means and to thereto, Said cover having the Same Configuration increase the wedging pressure per unit area of said as the rim of the container for fitting therein, said Sealing means acting against the inside walls f the cover having a reversible surface normally extendcontainer. ing downward y th r fr in a g n y COIWfiX 24. A closure adapted to seal a hot liquid container configuration and capable of being reversed into a as claimed in claim 23 including: concave configuration upon sealing of said closure reinforcing means associated with said sealing means due to the action of the internal. pressure for equally distributing the reaction radial forces generated by any heated gases present within the container, whereby the reversal of said reversible surface increases the effective volume of the sealed container thereby decreasing the resultant exerted on said sealing means from the container walls around said sealing means to maintain said sealing means in sealing contact with the inside walls of the container.

25. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein:

said lever means has a tapered configuration which includes two tab-like portions 180 apart whereby downward pressure simultaneously applied to said internal pressure of the container to increase the sealing capability of said closure.

22. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein:

said sealing means includes a cover connected 4Q thereto said cover having the same configuration as the rim of the container for fitting therein, said cover having a reversible bellows normally extending downwardly therefrom capable of reversing tab-like portions causes an initial angular reversal thereat which reversal moves along the taper in the form of a wave motion terminating along an axis which is located 90 opposite to the axis of the tablike portions to allow said sealing means to be into an upward position upon sealing of said closure due to the action of the internal pressure readly d'sengaged from the contamer generated by any heated gases present within the I 

1. A closure adapted to seal a container while being easily removable therefrom, said closure comprising: means for sealing the container, said sealing means having a tapering sealing portion arranged to mate with the inside walls of the container and capable of generating radial pressure thereagainst for maintaining wedging, sealing, contact therewith; and lever means extending radially outwardly from the container rim and being flexibly connected to said sealing means for providing sufficient mechanical advantage to release the closure from the container upon the application of sufficient downward force to said lever means whereby upon the application of sufficient force to said lever means said sealing means is readily disengaged from the walls of said container, said lever means being of sufficient strength to resist deflection under the application of the downward force and of sufficient width to be easily activated by human fingers; said lever means being arranged for contact with the rim of container and shaped so that upon application of the downward force the fulcrum will shift toward the point of application of the downward force along said lever means so that the ratio between the moment arms acting about the fulcrum is constantly changed during the application of the downward force, whereby maximum force is initially applied to break the seal generated by said sealing means and maximum motion is applied at the end of the application of the downward force to provide total separation between the closure and container.
 2. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein: said lever means includes reinforcing means to aid in resisting deflection upon the application of the downward force.
 3. A closure adapted to seal a container about its rim while being easily removable therefrom, as claimed in claim 1 wherein: said lever means extending radially outwardly from the container rim is in the form of a skirt adapted to provide a secondary seal against the rim of the container when the closure is inserted within the container.
 4. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 3 wherein: said lever means includes trusses extending radially along said radial skirt toward the inner and outer diameters thereof, whereby said radial skirt may be reversed into a downward and outward position relative to said sealing means under application of the downward force thereby emitting a snapping sound, said trusses being sufficiently narrow in width to permit reversal of said radial skirt between the portions of said lever means at which the downward force is applied.
 5. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 3 wherein: said lever means includes trusses extending radially to the outer diameter of said radial skirt to provide a gradual lifting and reversal of said radial skirt when acted upon by the dOwnward force without producing a snapping sound.
 6. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein: said lever means and said sealing means are abruptly connected, said lever means and said sealing means forming an abrupt intersection to provide abrupt reversal in the position of said lever means under the influence of the downward force to provide fracture and separation of said lever means from said sealing means during a second reversal.
 7. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein: said lever means and said sealing means form a slight radius at their connection to provide fracture and separation of said lever means relative to said sealing means during a subsequent application of the downward force.
 8. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein: said lever means and said sealing means form a radius at their connection, said radius being sufficiently large to prevent separation and fracture upon application of the downward force, while being sufficiently small to permit reversal in the position of said lever means.
 9. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein: said lever means and sealing means intersect abruptly at certain portions of their connection while the remaining portions of their connection have a slight radius to provide fracture at said abruptly intersecting portions while preventing complete separation of said lever means from said sealing means due to said slight radius connecting portions.
 10. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein: said lever means and sealing means are integrally connected, said closure having a memory of reversal at said integral connection.
 11. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein: said sealing means is shaped in the form of a truncated cone segment, said truncated cone segment being arranged for insertion of said sealing means into the container and having a taper which is substantially the same as the taper of the walls of the container, to provide wedging mating contact therewith, whereby said wedged truncated cone segment will generate radial pressure against the inside walls of the container forming a seal therewith.
 12. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 11 wherein: said truncated cone segment includes a plurality of sealing rings for line contact with the container walls to increase the sealing pressure therebetween, said sealing rings being of increasing diameter to match the taper of said truncated cone segment.
 13. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 11 wherein: said truncated cone segment includes reinforcing means for increasing the resistance of the sealing means to deflection while said sealing means is wedged against the inside walls of the container.
 14. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 13 wherein: said reinforcing means is an inwardly directed peripheral ridge of sufficient width and depth to further allow entrapment and cooling of portions of any heated gases and liquids present within the container, thereby creating a temperature differential along said truncated cone segment on the opposite sides of said ridge to increase the sealing capability of said sealing means and to increase the wedging pressure per unit area of said truncated cone segment acting against the inside walls of the container.
 15. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein: said sealing means has a low durometer to providE increased sealing action between said sealing means and the inside walls of the container.
 16. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein: said sealing means has a high coefficient of friction relative to the walls of the container to resist vertical displacement due to the action of any internal pressures resulting from any heated gases and liquids present within the container.
 17. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein: said lever means and sealing means are integrally formed of an impermeable material so that said closure is hermetically sealed to the container.
 18. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 including: reinforcing means associated with said sealing means for equally distributing the reaction radial forces exerted on said sealing means from the container walls around said sealing means to maintain said sealing means in sealing contact with the inside walls of the container.
 19. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein: said sealing means includes a cover connected thereto, said cover having the same configuration as the rim of the container for fitting therein, said cover further having stress distribution means for resisting deflection when the downward force is exerted thereupon to seal the container, said stress distribution means distributing the downward force radially to the periphery of said cover and therefrom to said sealing means.
 20. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein: said sealing means includes a cover connected thereto, said cover having the same configuration as the rim of the container for fitting therein, said cover further having a means for receiving and locating the bottom of a second container for wedging said cover into the first container and to stack individual sealed containers one upon the other for ease in transporting a plurality of individual sealed containers.
 21. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein: said sealing means includes a cover connected thereto, said cover having the same configuration as the rim of the container for fitting therein, said cover having a reversible surface normally extending downwardly therefrom in a generally convex configuration and capable of being reversed into a concave configuration upon sealing of said closure due to the action of the internal pressure generated by any heated gases present within the container, whereby the reversal of said reversible surface increases the effective volume of the sealed container thereby decreasing the resultant internal pressure of the container to increase the sealing capability of said closure.
 22. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein: said sealing means includes a cover connected thereto said cover having the same configuration as the rim of the container for fitting therein, said cover having a reversible bellows normally extending downwardly therefrom capable of reversing into an upward position upon sealing of said closure due to the action of the internal pressure generated by any heated gases present within the container, whereby the reversal of said reversible bellows increases the effective volume of the sealed container thereby decreasing the resultant internal pressure to increase the sealing capability of said closure.
 23. A closure adapted to seal a hot liquid container comprising: means for substantially hermetically sealing the container to effectively seal the inside of the container and any contents therein from its external environment, said sealing means having a configuration to mate with the inside walls of the container and arranged for wedging insertion into the container to generate radial pressure against the inside walls of the container forming a hermetic seal therewith; and at least one peripheral ridge of sufficient width and depth to allow entrapment and cooling of portions of any heated gases present within the container, thereby creating a temperature differential along said sealing means on the portions of said sealing means on opposite sides of said ridge to increase the sealing capability of said sealing means and to increase the wedging pressure per unit area of said sealing means acting against the inside walls of the container.
 24. A closure adapted to seal a hot liquid container as claimed in claim 23 including: reinforcing means associated with said sealing means for equally distributing the reaction radial forces exerted on said sealing means from the container walls around said sealing means to maintain said sealing means in sealing contact with the inside walls of the container.
 25. A closure adapted to seal a container while being easily removable therefrom, as claimed in claim 1 wherein: said lever means has a tapered configuration which includes two tab-like portions 180* apart whereby downward pressure simultaneously applied to said tab-like portions causes an initial angular reversal thereat which reversal moves along the taper in the form of a wave motion terminating along an axis which is located 90* opposite to the axis of the tab-like portions to allow said sealing means to be readily disengaged from the container. 